Modular construction system for a covered structure

ABSTRACT

The invention relates to a modular construction system for a covered structure of large section produced by assembling prefabricated elements, namely floor elements (1), side elements (2) placed on each side of the floor, and roof elements (4). 
     The structure according to the invention is composed of at least two juxtaposed passage sections (S, S&#39;) having parallel axes (0, 0&#39;), each bounded at the bottom by a floor element (1, 1&#39;) and at the top by a roof element (4, 4&#39;) and, at the sides, on the outside by a side element (2, 2&#39;) and on the inside by at least one intermediate pier (6) supported on the ground by means of a sole piece (7) interposed between the adjacent longitudinal sides (11, 11&#39;) of the two floor elements (1, 1&#39;) which frame it, said pier (6) being provided at the top with a longitudinal member (5) comprising two side walls (52) diverging in V-shape to form on each side of a median plane P1 two support surfaces (53) in the form of concave grooves on which rest the adjacent longitudinal sides (41) of the two roof elements (4, 4&#39;) framing the intermediate pier (6).

The present invention relates to a modular construction system for acovered structure of large section, and to a process for constructingthe same, and applies in particular to the construction of undergroundconduits or of buildings.

In the Applicants' European patent application No. 00 81 402 a processhas already been described for the construction of a covered structurein the form of a conduit of large section produced by assemblingprefabricated longitudinal elements, each of which forms only a part ofthe cross-section and which are connected together by optionallyarticulated longitudinal connections. This process, as describedtherein, is applicable to conduits or underground passages whosecross-section, which is preferably flattened at the base with awidth-to-height ratio of about 1.5, may be as great as 35 square metersor even more. It will be realized that it is difficult to give suchconduits a width of the order of two or three times their height, forexample, because it would then be necessary for the elements of thestructure to be reinforced in a prohibitive manner.

However, passages of great width are sometimes required, for example formultilane road underpasses, where a great height is not necessary and iseven inadvisable because of the uselessly entailed volume of earthwork,or where such a height is even inacceptable, for example because of theneed to confine the works to a prescribed maximum height.

Furthermore, in certain cases it may be advantageous to increase theground level area of the volume constructed and consequently for a givensection, to increase its width by reducing its height in comparison witha conduit of conventional section.

The present invention seeks to solve these problems by makingimprovements and extensions to the technique of constructing conduits oflarge section which is described in the above-mentioned European patentapplication.

In a general way, a large-section conduit of this kind is produced byassembling prefabricated elements, namely flat elements forming a floor,side elements disposed on each side of the floor, and roof elements ofcurvilinear profile resting, preferably with interposed articulatedsupports, on the top ends of the side elements, the latter including acurved wall whose inner profile joins at the top that of the roofelements and, at the bottom, the horizontal floor. In addition, the sideelements rest on the ground with interposed external stabilizers, whichgive them sufficient support to enable them to stand upright withoutadditional supports, scaffolding, or the like.

The present invention covers a modular construction system for a coveredstructure composed of at least two sections lying side by side andhaving parallel axes, each bounded at the top by a floor element, at thebottom by a roof element, and, at the sides, on the outside by a sideelement and on the inside by at least one intermediate pier supported onthe ground by means of a sole piece interposed between the floorelements framing it; said pier supports an intermediate longitudinalgirder comprising two side walls diverging in V-shape so as to form twosupport surfaces in the form of concave grooves on which rest theadjacent longitudinal sides of the two corresponding roof elements.

In a first embodiment each intermediate pier is composed of a verticalwall, in which openings are optionally formed and which is provided atits base with a continuous sole piece, while its top part forms theintermediate longitudinal support girder for the roof elements.

In another embodiment each intermediate pier is composed of a series ofpillars provided at their base with individual support sole pieces,which are laid between the adjacent longitudinal edges of the floorelements, the gaps between the floors and between the sole pieces beingconcreted after laying, in order to join the whole arrangement together.The intermediate longitudinal member may advantageously be extended,above the supports, by a shouldering beam of sufficient height to enableit to withstand the bending forces occurring during use, taking intoaccount the spacing of the pillars.

The invention also covers the process for the construction of astructure of this kind, which comprises the following stages:

The ground having been previously prepared to form a resistant beddingsurface at the desired level, a number of floor elements correspondingto the number of sections to be constructed are first placed on theground, optionally cemented in place, and aligned on the axes of saidsections. The piers are then placed between the floor elements and theincurved side elements are placed along the outer sides, leaving a spacebetween the opposite longitudinal edges. Like the side elements, thepiers must be sufficiently firmly seated to stand upright by themselves.If the piers are composed of spaced pillars, longitudinal beams are thenplaced on their tops to form the intermediate longitudinal girders andjoined to the pillars. If the piers are composed of vertical walls,their tops will themselves form the longitudinal girder.

It is then possible to place the roof elements in position one after theother, resting them by their longitudinal edges, on the outside, on theside elements and, on the inside, on the support surfaces provided alongthe intermediate longitudinal girders.

Concrete is finally poured to fill the spaces left between the floorelements, the side elements, and the sole pieces of the piers, so as tojoin the whole arrangement together.

The conduit is formed in this way, advancing portion by portion.

According to advantageous procedures: the different elements of theconduit may be joined with pretensioning;

at least some of the connections between longitudinal elements areplaced in stress nodes, that is to say zones where the absolute value ofthe stresses passes through a minimum;

at least some longitudinal connections between two adjacent elementsconstitute in each case an articulation permitting a limited angulardisplacement;

these articulated connections are situated in zones where the absolutevalue of the stresses passes through a minimum.

The invention will now be described in greater detail with the aid ofpractical examples, which are given without constituting limitations andare illustrated in the drawings, in which:

FIG. 1 is a cross-section of a structure produced in accordance with theinvention;

FIG. 2 is a detail view of the supports on the intermediate longitudinalgirder.

FIG. 3 is a detail view in perspective of another embodiment;

FIG. 4 is a diagram in perspective showing the construction of amulti-section structure.

The structure shown in the drawings is intended, for example, to hold atwo-lane motor carriageway. It is composed of prefabricated reinforcedconcrete elements. As in the case of the previously mentioned EuropeanPatent No. 0080.402, these elements comprise, in cross-section, floorelements 1, side elements 2, and roof elements 4.

For the construction of a structure of this type, forming asingle-section conduit, the floor elements are first placed on theground 10 previously prepared at the desired level, and may optionallybe cemented in place. Floor elements may also be placed in advance overa certain length and aligned along the axis of the conduit being built.According to a particularly advantageous characteristic of the inventionthe same prefabricated elements may be used for the construction ofstructures comprising a plurality of juxtaposed sections in accordancewith a modular system.

FIG. 1 shows by way of example a structure comprising two juxtaposedsections whose axes 0, 0' are spaced a distance 1 apart which is soselected that between the roof elements 4, 4' a sufficient space is leftto receive an intermediate longitudinal support girder 5.

For the construction of a structure of this type, therefore, twoparallel series 1 and 1' of floor elements will be placed in position,leaving between their adjacent longitudinal edges 11 and 11' a distance(e) depending on the distance between centers (1).

Between the adjacent longitudinal edges 11 and 11' of the floor elements1 and 1' is placed a vertical support element 6 forming a pier, which atits base is provided with a support sole piece 7 and is surmounted by alongitudinal girder 5. The latter is bounded by two side walls 52diverging in V-shape, in such a manner as to provide at its upper part,two support surface 53 of identical shape, at the top longitudinal edges22 that the side elements 2. These support surfaces 53 will thereforepreferably be in the form of concave circular grooves, on which rest therounded longitudinal edges 41 of the roof elements 4, in such a manneras to form a support articulated about a longitudinal direction.

The width of the support sole piece 7 is determined in dependence on thedistance (e) between the inner longitudinal edges 11, 11' of the roofelements 1, 1', in such a manner that between the latter and the edges71 of the sole piece a space 9 is left which provides a certainadjustability of the position of the pier 6.

On each side of the outer edges 12 and 12' of the floor elements arethen placed the incurved side elements 2 and 2'. In accordance with anarrangement already described in the previous patent, these elements arecomposed of an incurved wall whose inner profile 20 has a variablecurvature enabling it to be connected at the bottom to the tophorizontal portion of the floor 1, and at the top to the circularprofile of the roof element.

The position of the inner longitudinal edges 23 of the side elements 2is determined in such a manner that, taking into account their seatingarea and the distribution of loads, said elements will stand upright bythemselves, without scaffolding, even when they support at their topends 22 the dead weight of the roof elements 4 while leaving, betweenthe inner longitudinal edges 23, 23' and outer longitudinal edges 12,12' respectively of the side elements 2, 2' and floor elements 1, 1' aspace 8 of sufficient width (a) to allow accurate adjustment of theposition of the side element 2, 2' on installation.

After the elements have been installed, the adjustment spaces 8 and 9are cemented up to effect the locking-in of the floor, loops ofconnecting iron bars being left for this purpose on the sides of theelements. Longitudinal reinforcements 16 are threaded through theseloops 15 so as to achieve continuity of the locking action and tohomogenize deformation between successive sections of the conduit.

In accordance with an arrangement described in the previous patent, theside elements 2, 2' are provided at their base, on the outer side, withstabilizers 21 of triangular section, which may extend over the entirelength of the side element or, as can be seen in FIG. 4, may consist ofregularly spaced prismatic elements.

The bottom part 24 of the outer face 25 of the incurved wall isadvantageously plane and inclined, for example with a ratio of 3:1 inrelation to the base, in such a manner as to facilitate the compactingof the backfilling on the outer sides.

The elements are so designed that when they are under load, under thebackfilling, the stresses which occur are transmitted in substantiallytangential directions from the roof element 4 to the side element 2,while the support reactions then pass substantially at the centre of thearticulation. On the other hand, when the roof element 4 is installedand is loaded solely by its own weight, it will exert on the ends of theside elements 2, vertical forces F which will be applied to horizontaltangent plane parts of the grooves 22.

The support grooves 53 provided on each side of the longitudinal beams 5are of entirely identical construction to the support grooves 22 of theside elements 2, and the width of the longitudinal member is made sothat the support loads F' will not be far from the median plane P1 ofthe pier 6. The width of the sole piece 7 can be so determined as toenable the pier 6 to stand upright by itself, without scaffolding, whileleaving an adjustment space 8 at its sides.

It will in fact be observed that, taking into account the dimensionsrequired for withstanding the loads due to the backfilling, the roofelements 4 are relatively rigid and are not liable to be deformed undertheir own weight; consequently, on installation, the loads applied tothe supports 5 have practically no horizontal component. Thus, after apier 6 has been installed between the floors 1 and 1' and side elements2 and 2' of the latter, it will be possible for one roof element 4 andthen the other 4' to be placed in position in succession, there being norisk that the pier 6 will be overturned when it is loaded on one sideonly, particularly as friction between the edges of the roof element andthe support grooves also contributes towards the stability of theintermediate piers. Obviously, when the two roof elements 4 and 4' arein place, the whole arrangement is perfectly stable, the longitudinalmember 5 being equally loaded on both sides. The entire floor can thenbe joined together and locked in place by cementing up the spaces 8 and9 left between the longitudinal edges of the floor and, respectively,the side elements 2 and the sole piece 7 of the pier 6.

If the side elements and the piers 6 are so designed as to stand up inthe vertical position by themselves, it is obviously preferable forthese elements to be supported during installation by removable props 13and 14 disposed between the floor and, respectively, the side elements2, 2' and the pier 6. There is in fact always some risk of incorrecthandling, for example the swaying of the roof element while it is beingplaced in position, which would accidentally subject the supportelements to horizontal forces capable of overturning them. However, thissystem of props can be light and can be removed as soon as the roofelements 4 and 4' have been placed in position on each side of thecentral pier.

FIG. 1 shows a structure comprising two juxtaposed sections, but thesame system of modular construction could be extended to multisectionstructures as shown in FIG. 4, for example for the purpose ofconstructing a conduit having a very large section or a multilane roadpassage.

In the example shown in FIG. 4, the central pier is a solid verticalwall, in which doors may optionally be formed. However, in certain casesit may be desirable to construct it in the form of spaced pillars, asshown in FIG. 3, or even in the form of oblique beams. In view of theadvantages achieved through the construction of the conduit inaccordance with the invention, particularly the fact that it can bebuilt quickly and with a very small team (for example 4 persons), theinvention is in fact not limited solely to the construction of sunkenpassages or conduits, but may also be of advantage for otherapplications, for example the construction of industrial buildings ordwellings. In this case the building will be composed of parallel aislesand it is more advantageous to make the piers in the form of spacedpillars to allow communication between aisles, as shown in the partialview in FIG. 3.

If the strength of the ground allows, it is advantageous to limit thenumber of pillars by increasing their span. To ensure that theintermediate longitudinal member 5 will retain sufficient flexuralstrength between supports, it is expedient to increase its height byextending it in the upward direction, above the supports 52, by means ofa shouldering beam 54 whose height is determined in dependence on theloads supported and the reinforcement which it is possible to placethere. However, this additional height h will preferably not be greaterthan the sag of the roof element 4, in order not to go beyond the toplevel of the latter.

When the floor is sealed in, not only the joints 9 between the solepieces 70 of the pillars 60, but also the spaces 72 left between thepillars, will be cemented. In a general way, moereover, the seatingsurface and the reinforcement of the sole pieces 70 and of theirjunction to the floor will be designed in accordance with the loadssupported by the pillars 60 and with the strength of the ground.

All the prefabricated elements constituting the conduit will normally beof concrete, but in accordance with an arrangement already provided forin European Patent No. 0081 402 it is possible for certain elements tobe made differently, particularly the roof elements. Thus, in the caseof the construction of industrial buildings, it could be of interest toconstruct the roof elements in the form of panels of metal or plasticmaterial, optionally corrugated, while they could also be provided withlighting openings.

The invention is obviously not limited to the details of theembodiments, which have been described only by way of example, whileother variants could be conceived without departing from the scope ofprotection defined by the claims.

I claim:
 1. Modular construction system for a covered structure of largecross-section produced by assembling prefabricated elements, each ofwhich forms only a part of the perimeter and which comprise respectivelyplane elements (1) forming a floor laid on the ground, side elements (2)placed on each side of the floor, and roof elements (4) of curvilinearprofile resting, with interposed articulated supports (41), on the topends of the side elements (2), the latter including an incurved wallwhose inner profile joins at the top that of the roof element (4) and,at the bottom, the top face of the floor (1), said incurved wall restingon the ground with interposed external stabilizers (21), which give themsufficient support to enable them to stand upright without additionalsupport, the floor elements (1) being fastened at least to the base ofthe side elements (2) by sealing-in after installation, this structurebeing characterized by the fact that it is composed of at least twosections (S, S') lying side by side and having parallel axes (0, 0'),each bounded at the bottom by a floor element (1, 1'), at the top by aroof element (4, 4'), and, at the sides, on the outside by a sideelement (2, 2') and on the inside by at least one intermediate pier (6)supported on the ground by means of a sole piece (7) interposed betweenthe adjacent longitudinal sides (11, 11') of the two floor elements (1,1') framing it, said pier (6) being provided at the top with alongitudinal member (5) comprising two side walls (52) diverging inV-shape so as to form two support surfaces (53), one on each side of amedian plane P₁, which are in the form of concave grooves on which restthe adjacent longitudinal sides (41) of the two roof elements (4, 4')framing said intermediate pier (6).
 2. Structure according to claim 1,characterized in that each intermediate pier (6) is composed of avertical wall, in which openings are optionally formed and which isprovided at its base with a continuous supporting sole piece (7), whileits top part forms the intermediate longitudinal girder (5) supportingthe roof elements (4, 4').
 3. Structure according to claim 1,characterized in that each intermediate pier (6) is composed of a seriesof pillars (60), each provided at its base with an individual sole piece(70) and supporting a longitudinal beam (5) forming the longitudinalgirder the gaps (72, 9) between the floors (1, 1') and between the solepieces (70) being concreted after laying in order to effect thesealing-in of the floor.
 4. Structure according to claim 3,characterized in that the longitudinal beam (5) constituting thelongitudinal member is extended above the supports (53) by a shoulderingbeam (54) of sufficient height to enable it to withstand the bendingforces occurring during use, taking into account the spacing of thepillars (60).
 5. Structure as in any one of the preceding claims,characterized in that the profile of the pier (6) is so designed thatsaid pier will be stable even when it is located on one side only duringthe installation of roof elements (4).
 6. Structure as in any one ofclaims 1-4, characterized in that the floor elements (1), the bases ofthe side elements (2), and the sole pieces (7) of the intermediate piers(6) are provided on their longitudinal sides with connection bars inloop form which intercross in the spaces (8, 9) left between the sidesof said elements and into which are threaded longitudinal reinforcements(16), the whole arrangement being concreted to effect continuoussealing-in and the homogenization of deformations between the successiveportions of the structure.
 7. Process for the construction of a coveredstructure of large section, produced by assembling prefabricatedelements and comprising, in accordance with claim 1, at least twojuxtaposed sections (S, S') having parallel axes (0, 0') and separatedby an intermediate pier (6), characterized by the fact that theconstruction is effected on ground previously prepared at the desiredlevel, in accordance with the following stages:floor elements (1, 1')are placed on the ground, optionally cemented in place, and aligned onthe axes (0, 0') of the sections which are to be built; the incurvedside elements (2, 2') are placed along the respective outer longitudinaledges (12, 12'), and the intermediate piers (6) are placed between theadjacent longitudinal edges (11, 11') of the floor elements (1, 1'),said side elements (2, 2') and piers (6) being sufficiently firmlyseated to stand upright by themselves and the piers (6) being providedat the top with longitudinal support members (5); the longitudinal roofmembers are placed in position one after the other, resting them bytheir longitudinal edges, on the outside, on the side elements (2, 2')and, on the inside, on the support surfaces (53) of the longitudinalmembers (5); concrete is poured to fill the gaps between the floorelements (1, 1'), the bases of the side elements (2, 2') and the solepieces (7) of the piers (6), in such a manner as to join them together.8. Process according to claim 7 for the construction of a coveredstructure in which the piers (6) are composed of spaced pillars (60),characterized by the fact that after the pillars (60) have been placedin position between the floor elements (1, 1'), longitudinal beams (5)are laid on their top part to form the longitudinal support girderswhich are then fastened to the pillars (60).